Simplify the following expression: $y = \dfrac{2}{5x + 4} \div \dfrac{4}{7x}$
Dividing by an expression is the same as multiplying by its inverse. $y = \dfrac{2}{5x + 4} \times \dfrac{7x}{4}$ When multiplying fractions, we multiply the numerators and the denominators. $y = \dfrac{ 2 \times 7x } { (5x + 4) \times 4}$ $y = \dfrac{14x}{20x + 16}$ Simplify: $y = \dfrac{7x}{10x + 8}$